To understand my current situation we have to go back to around three weeks ago when I decided to take my UIM off to clean up some wires. I took off the UIM and set the throttle cable down. The cable touched the main power wire coming off the alternator and sparked and bured through. (I was going to disconnect the battery before snipping the wires.) I thought i had taped this up very well because i had seen this type of thing happen before and wanted to avoid it (oh well too late now). So my throttle cable is toast. I then continued to take off my UIM. I smelled gas so I started to investigate. My Fuel Pulsation Dampener was leaking out the top of it. One more thing to order from Mazda.

I ordered my parts from Mazda and they will be here in a few days. I thought I would use this time to install my DEFI D-series Fuel Pressure Gauge. After a few trips to Home Depot i got it sorted out. The throttle cable and the FPD came in and I installed both of those without any problems. I primed the fuel system and went to start it.

When I started the car it runs extremely rich and vaporized fuel spews out the tail pipe. It sounds like it is running on one rotor. When i run it for a long time the inside of my tail pipe glows red, which is frightening.

Now its time to think. What could be the problem. My engine is very new and I broke it in properly. It was running fine the last time i drove it. I also thought my plugs were fouled from sitting so long. I changed those. It runs the same. Maybe one of my ignitions coils is bad. I tested for spark on all 4 and it was good on all of them. Somehow i thought putting in the Fuel Pressure Gauge in the line might have effected it. I swaped it out for the original line and had no change. I tried messing with the A/F screws and it helped a little but still did nothing. I moved the car the other day and didnt let it warm up enough so now it is sitting in the garrage flooded. I pulled the trailing plugs and cranked with WOT for 20 seconds. I repeated this a few times. It acted like it allmost wanted to start but it didnt. I got frustrated and had to walk away.

This is where i'm at right now. I would really appreciate some advice or some suggestions on where I should go from here. Thanks.

 

Check your map sensor.

 

It is hooked up correctly. Is there any other way I can test it to see if its working? Or, is my only alternative to replace it and hope for the best?

 

Bump. Any Ideas?

 

Do you think my FPR could be malfunctioning? My DEFI gauge read around 40. It is hooked up correctly.

 

Chris
Do a compression test to rule out a problem there.

Jeff

 

Yea i have been kind of avoiding that because the news of a blown engine would really be a downer. It needs to be done though.

 

It almost sounds like it was flooded to begin with. I'd say start it (either ATF or push start) and let it run until it warms up and see if the symptoms dissapear. I can't imagine anything you'd have done would have had any affect on the engine. You can't blow an apex seal with an arc, at least I don't think so

 

Beleive me I ran it for an hour or two on more than one occasion. I drove it around and let it warm up completely. The exhaust tip started to glow red and sother things started to scare me a little so i shut it down.

Maybe the PFC is fried? Would replacing it with my stock computer let me know if it was?

 

Ok then, I didn't know that. If it's running that hot theres definitely a problem somewhere (yeah I know, thanks for pointing out the obvious 911GT2)

How modded is your car? If it'll be safe to run it with the stock ecu (i.e. stock boost levels, seq twins) then that would be a good test to try. It could have shorted out the PFC when the throttle cable arced.

 

Yeah... DEFINATELY try a different computer.

 

TO4S, 5 lbs of boost, stock injectors. I think that might be safe. I wouldnt push it at all.

The Glowing tail pipe definitely scared me.

 

HAHA if Eric ever gives it back!

 

Get a hold of AdamRX7. He has my stocker... You can use that. You'll have to find him on the stlstreetracing forum though... Dont think he's here.

 

Yikes. I wouldn't put the stock ECU in with a single in their. But maybe if it's just to start and idle it it'd be ok? Not sure, I'd talk to someone with a single turbo first just to see if it's ok.

 

I'm sure it will be ok. Im just running the stock map with the fuel bumped up on the PFC for now anyways. I think idle will be ok.

 

He'll be fine as long as it's just to see if the idle cures... It'll throw engine codes all over the place due to the missing plugs and no restrictors, but it'll rule the computer in or out. Might even go into limp... But it should still diagnose the ECU.

 

dude u need an aftermarket fuel pressure regulator. same problem im having i just need to figure out how to tap it in

 

I was under the impression that the stock FPR was good enough because I'm not doing crazy stuff with fuel right now.

 

i agree that you need to change out the PFC for someone elses PFC or for another ECU if thats still safe.

If that doesn't work and if you REALLY think its just the engine running rich, as a TEMPorary test, trying taking the PIM setting for 1000rpms down to like 85% or something and see if that helps lean it out enough to fix things. HOWEVER, considering how HOT it was running with the glowing tailpipe, etc., its probably NOT running rich and you probably DON'T want to lean it out, but the PIM voltages are an easy quick fix for a very rich idle if thats definitely your problem.

-Rob

 

I got it started again. I just have to see if replacing a few things will cure it. I'll change out the ECU and let you know if it fixes it.

 

I'm going to sound like a dumb-*** for relating this, but when I did my single conversion, I mistakenly attached the map sensor vacuum line to what felt like a UIM vacuum nipple, but was actually a rod from the throttle body butterfly. What can I say--it was 3 am and I had been working on the car for 8 hours.

Anyway, double check where on the UIM you have your map sensor vacuum line attached.

 

ive checked that map sensor around 45 times. Its good.

 

Ok i found something new. The Load on my maps for the PFC does not change. I have no idea what could cause this. Any ideas?

Here is the thread in the PFC section: https://www.rx7club.com/showthread.p...hreadid=246114

 

maybe its this